<?php  //$Id: delete_category_form.php,v 1.1.2.3 2008/12/08 07:28:05 tjhunt Exp $

require_once($CFG->libdir.'/formslib.php');
require_once($CFG->libdir . '/questionlib.php');

class delete_category_form extends moodleform {

	var $_category;

	function definition() {
		global $CFG;

		$mform	=& $this->_form;
		$category = $this->_customdata;
		ensure_context_subobj_present($category, CONTEXT_COURSECAT);
		$this->_category = $category;

	/// Check permissions, to see if it OK to give the option to delete
	/// the contents, rather than move elsewhere.
	/// Are there any subcategories of this one, can they be deleted?
		$candeletecontent = true;
		$tocheck = get_child_categories($category->id);
		$containscategories = !empty($tocheck);
		$categoryids = array($category->id);
		while (!empty($tocheck)) {
			$checkcat = array_pop($tocheck);
			$childcategoryids[] = $checkcat->id;
			$tocheck = $tocheck + get_child_categories($checkcat->id);
			if ($candeletecontent && !has_capability('moodle/category:manage', $checkcat->context)) {
				$candeletecontent = false;
			}
		}

	/// Are there any courses in here, can they be deleted?
		$containedcourses = get_records_sql("
				SELECT id,1 FROM {$CFG->prefix}course c
						WHERE c.category IN (" . implode(',', $categoryids) . ")");
		$containscourses = false;
		if ($containedcourses) {
			$containscourses = true;
			foreach ($containedcourses as $courseid => $notused) {
				if ($candeletecontent && !can_delete_course($courseid)) {
					$candeletecontent = false;
					break;
				}
			}
		}

	/// Are there any questions in the question bank here?
		$containsquestions = question_context_has_any_questions($category->context);

	/// Get the list of categories we might be able to move to.
		$testcaps = array();
		if ($containscourses) {
			$testcaps[] = 'moodle/course:create';
		}
		if ($containscategories || $containsquestions) {
			$testcaps[] = 'moodle/category:manage';
		}
		$displaylist = array();
		$notused = array();
		if (!empty($testcaps)) {
			make_categories_list($displaylist, $notused, $testcaps, $category->id);
		}

	/// Now build the options.
		$options = array();
		if ($displaylist) {
			$options[0] = get_string('movecontentstoanothercategory');
		}
		if ($candeletecontent) {
			$options[1] = get_string('deleteallcannotundo');
		}

	/// Now build the form.
		$mform->addElement('header','general', get_string('categorycurrentcontents', '', format_string($category->name)));

		if ($containscourses || $containscategories || $containsquestions) {
			if (empty($options)) {
				print_error('youcannotdeletecategory', 'error', 'index.php', format_string($category->name));
			}

		/// Describe the contents of this category.
			$contents = '<ul>';
			if ($containscategories) {
				$contents .= '<li>' . get_string('subcategories') . '</li>';
			}
			if ($containscourses) {
				$contents .= '<li>' . get_string('courses') . '</li>';
			}
			if ($containsquestions) {
				$contents .= '<li>' . get_string('questionsinthequestionbank') . '</li>';
			}
			$contents .= '</ul>';
			$mform->addElement('static', 'emptymessage', get_string('thiscategorycontains'), $contents);

		/// Give the options for what to do.
			$mform->addElement('select', 'fulldelete', get_string('whattodo'), $options);
			if (count($options) == 1) {
				$mform->hardFreeze('fulldelete');
				$mform->setConstant('fulldelete', reset(array_keys($options)));
			}

			if ($displaylist) {
				$mform->addElement('select', 'newparent', get_string('movecategorycontentto'), $displaylist);
				if (in_array($category->parent, $displaylist)) {
					$mform->setDefault('newparent', $category->parent);
				}
				$mform->disabledIf('newparent', 'fulldelete', 'eq', '1');
			}
		} else {
			$mform->addElement('hidden', 'fulldelete', 1);
			$mform->addElement('static', 'emptymessage', '', get_string('deletecategoryempty'));
		}

		$mform->addElement('hidden', 'delete');
		$mform->addElement('hidden', 'sure');
		$mform->setDefault('sure', md5(serialize($category)));

//--------------------------------------------------------------------------------
		$this->add_action_buttons(true, get_string('delete'));

	}

/// perform some extra moodle validation
	function validation($data, $files) {
		$errors = parent::validation($data, $files);

		if (empty($data['fulldelete']) && empty($data['newparent'])) {
		/// When they have chosen the move option, they must specify a destination.
			$errors['newparent'] = get_string('required');
		}

		if ($data['sure'] != md5(serialize($this->_category))) {
			$errors['categorylabel'] = get_string('categorymodifiedcancel');
		}

		return $errors;
	}
}
?>
